Acute episodes of bronchitis in cigarette smokers are a major health problem and are in particular a cause of morbidity and mortality with patients with chronic obstructive lung disease (COLD). The upper respiratory tract of these patients is commonly colonised with Haemophilus influenzae and/or Streptococcus pneumoniae, and it has been held that a shift in the shot-bacteria balance favouring infection with these organisms is the immediate cause of acute bronchitis. Children with cystic fibrosis commonly suffer from chronic infection by Pseudomonas aeruginosa and Staphylococcus aureus. Polybacterial vaccines containing a selection of killed bacteria normally associated with infection of the respiratory tract have been available for many years. The polybacterial vaccines contain an adjuvant of conventional type whose function according to established methodology is to enhance the response of the patient to the antigen thereby leading to enhanced immunity. The adjuvant may be a chemical agent. Alternatively, the variety of organisms themselves function in a non-specific way to activate the immune system. Such adjuvant-containing polybacterial vaccine has been commercially available in tablet form for oral digestion. The tablets are enteric coated to allow passage through the stomach, followed by stimulation of gut-associated lymphoid tissue. However, the effectiveness of these polybacterial vaccines has been disappointing in the treatment of acute bacterial infections of the respiratory tract in humans having chronic mucosal inflammations.
It is an object of the present invention to provide an enteral vaccine against infections of mucosal surfaces in humans having long term mucosal disease.